Hailey Potter and the Runes of Elemental Power
by Eau-de-Glace
Summary: AU Philosopher's Stone. Harry Potter has a twin sister that we did not know of, up until she went to Hogwarts. Raised by James' younger brother, she grew up to be a prankster but a responsible and talented child. However, she got sorted with the snakes. Full summary inside. Disclaimer: I do not own Harry Potter. Rated T because I'm paranoid. A collaboration with Darklight Blue.
1. Chapter 1: The Legendary Halloween

**_Summary:_** _AU Philosopher's Stone. Harry Potter has a twin sister that we did not know of, up until she went to Hogwarts. Raised by James' younger brother (OC), she grew up to be a prankster but a responsible and talented child. However, imagine the Potters' (including Harry) surprise when she got sorted in the House of Snakes. A bit crestfallen, Hailey Potter manages to find comfort in the name of one Harmony Pettifogger and together, they have an adventure even more dangerous than the Golden Trio's._

 ** _Disclaimer:_** _I do not own Harry Potter_

* * *

On the night of October 31, 1981, Edward Potter and his wife Catherine went to Godric's Hollow to ask Lily and James if Hailey could go over their house for the night.

The Potter's house was placed in between two muggle houses, not that they could see them. They were protected by the Fidelius Charm, in which it will not be seen unless the secret-keeper tells them the place. The Potter's secret-keeper was Peter Pettigrew, a short, blonde hair man with bald top and rabbit-like teeth. He was a Marauder and one of James' best friends.

They drew closer to the door and knocked. After a few seconds, the door opened to reveal a tired but grinning James Potter. Judging on how he looks, he was obviously playing with the twins. He let the couple in.

"What do we owe the pleasure, my DEER ol' bro?" James asked with a mock bow, his signature teasing smile hidden beneath the bow.

"Stop being such an idiot, James. We just wanted to ask you if Hailey could go over our house for the night to give you and Lily a rest," Edward asked. Catherine chuckled at Edwards retort towards James.

James's smile turned into a genuine one and said, "Lily and I would be glad. Those kids are really hyper, especially my girl."

As if on cue, the kitchen door flew open to reveal a shrieking young boy with messy black hair and a girl with short black hair in pigtails running after him. The boy ran to James and the girl chased him, circling James.

Edward and Catherine laughed at the twins' antics. "They sure really are hyper," Catherine laughed.

The boy pretended to cry while clutching his father's left leg. He was pointing to the girl. The girl saw the boy's action, sniffed sadly, and went to the boy, hugging him.

The scene lasted for moments, until the boy hit the girl on the head lightly.

"Howie!" The girl shrieked again but before they could continue their chase, Edward picked up 'Howie' and James picked up his daughter, with 'Howie' blowing raspberries at the girl.

"Hey there, kid. Care to say your name?" Grunting, Edward asked the girl, who was struggling to blow raspberries too. Her hands were on either side of her head and she was shutting her eyes forcefully to concentrate.

She looked at him in the eyes, imitating his facial features (except that her hair is in pigtails), and said "Howie" seriously.

Catherine laughed. "So your names are both 'Howie' now, eh?"

"No! She Helee! She Helee!" Harry argued. James's daughter puffed out her cheeks in irritation to Harry's remark

It all happened in a matter of seconds: the twins switched places, which is quite usual when happening to the two of them. 'Helee' sneezed while 'Howie' yawned. Catherine now took Hailey from Edward and hugged her. "Aw, you two are so adorable," Catherine said, pinching Hailey's cheek.

The twins both giggled and Lily came out of the kitchen door. "Dinner is served," she said before walking back in. No one really noticed her smile as she walked back.

Dinner was composed of all their favorites, much to the pleasure of the Potter brothers. They sat down on the table, Lily on James's right, Catherine on Edward's left, and the twins in the middle of the two couples.

The dinner was rather uneventful except for Harry blowing raspberries at Hailey, taunting her. Hailey was struggling to do it but continuously failed which resulted for a fit of chuckles that came from the adults.

After cleaning up, Edward and Catherine picked up Hailey, who was giggling on the floor, and bid their goodbyes. James kissed his only daughter and Lily hugged her. "Be safe," James and Lily bid them as Harry clung on his father's leg, watching his aunt and uncle disappear with his sister.

Not long after they departed, Voldemort came to Godric's Hollow. Lily and James were killed but Harry survived, not without a mark on his forehead. Edward and Catherinelearned their unfortunate fate and went there. They mournedfor the loss of their other family, for the twins to be orphans. Their heart went out for brave little Harry and sweet naive Hailey. They were too late; for they found nothing except for a letter addressed to them:

* * *

Edward and Catherine,

Harry's safe at the Dursleys.

A.P.W.B.D.


	2. Chapter 2: The Meeting of the Twins

**_Summary:_** _AU Philosopher's Stone. Harry Potter has a twin sister that we did not know of, up until she went to Hogwarts. Raised by James' younger brother (OC), she grew up to be a prankster but a responsible and talented child. However, imagine the Potters' (including Harry) surprise when she got sorted in the House of Snakes. A bit crestfallen, Hailey Potter manages to find comfort in the name of one Harmony Pettifogger and together, they have an adventure even more dangerous than the Golden Trio's._

 ** _Disclaimer:_** _I do not own Harry Potter._

* * *

It was a sunny day in London. As people in a train station hurried around, a queer-but-normal looking family also hurried, almost that if anyone looks closely at them, they could see smoke seeping out from the family's shoes. A girl ran towards the barrier leading to Platform 9 3/4 with two people who, with their looks, could be considered her parents, but they were actually her aunt and uncle trailing behind.

"Hailey, you cheetah of a woman! Wait for us!" the voice of her uncle could be heard above the noise and conversations of the crowds. "And your dress is crinkled too!"

"It's not my fault you're getting slow already. I'm not going to catch the train if I slow down! And I don't want to be late for my first year! Also, my dress is not crinkled!" the girl could be heard retorting as she suddenly disappeared from the crowds through the barrier.

As the girl passed through the barrier, she saw the beautiful scarlet train of Hogwarts Express when she reached the end. The train looked majestic and ancient, it being a steam-powered train and decorated in some of the most regal colors. Her jaw became slack and she stopped to stare at the train as her mouth formed an 'o'. It was a dream beyond belief, she concluded, to go to the most esteemed and respected wizarding school in Scotland.

"I can't believe it," she breathed in awe. "I'm going to the most prestigious wizarding school ever."

Uncle Edward and Aunt Catherine jogged and caught up behind her. "Ready?" her aunt asked as her uncle stopped to catch his breath.

"As ready as I'll ever be," the girl nervously replied, clutching her shoulder bag and her trolley tightly. As they walked into the nearest compartment, her aunt saw some friends of hers and waved. Her friends, who were accompanying their children into the train, waved back and quickly flicked their wands, magic enveloping luggages and carts and easily floating it into the train. One of the children that were inside one of the carriages, a poker-faced girl with half of her brown hair that covered her face waved at her father, who in turn, walked closer and kissed her forehead, making her form a temporary smile that quickly faded as the father left to talk to Hailey's aunt.

Her aunt flashed a quick smile at her uncle and her as she took a step forward to talk to the father. Her uncle, having gotten the message, tapped his niece's shoulder and pointed to an empty carriage. The girl got the idea and began to walk faster towards the train. She, with the help of her uncle, heaved the luggage up the train door. Then, she directed the luggage to the empty compartment, where she picked the seat next to the window and put a cage on it. A ruffled hoot and flashing of feathers greeted her coldly and she turned to look at the cage, where a brown horned owl was stationed inside. It hooted again and she smiled sheepishly at the ruffled owl.

"Sorry 'bout that, Ying," she apologized, "But will you wait a few more hours before going away?" A hoot came out from the owl and she shrugged. "I'll be going outside for a while."

She hopped down from the train where she saw her uncle talking to the same man beside her aunt. It seemed like they were life-long friends and were just getting updated on the events. Shrugging again, she walked around as people jostled around her. She looked up and saw the clock which read ten minutes to eleven. Whistling, she explored around until she found a small portable vending machine. She slipped in front of it and wondered what drink should she buy in case. Her eyes wandered to a red bottle with the label of 'Kapika 72 degrees coffee latte'.

She bought the small red bottle. Walking to a nearby bench, she positioned herself before opening the bottle and tasting its contents. When she nearly emptied the liquid contents of the coffee latte, she stood up and absentmindedly went to find for a trash can. While doing so, she accidentally tripped on something slippery and fell down on a passing person.

"Sorry," the person's voice was quivering nervously and she immediately felt guilty. She proceeded to stand quickly and held out her hand for the person. She then realized she was looking at a raven-haired boy who was sitting up in the midst of the crowd.

"No, no, no. I'm the one who should be sorry. I'm Hailey by the way, Hailey Potter. What's yours?" she asked as the boy gratefully took her hand and stood up with her help.

After dusting his pants, he replied, "Harry. Harry Potter. We do seem to share the same surname," he quickly added as he saw the girl in front of him quiver and become dumbstruck and frozen, "don't we?"

"H-Harry?"

"Yes, Harry," he responded with uncertainness and hesitance in his voice, as if he was shyly confirming his name in front of a gigantic crowd and that the crowd would glomp on him. He clearly didn't want the attention.

Her eyes traveled up to his disheveled hair and she caught a glimpse of what could somehow be inferred as an inverted 'Z' or a thunderbolt. Harry was in front of her; she can't believe it was fated to be her lucky day. She found her missing-in-action twin.

She suddenly hugged him. "We've been waiting for you to come! I've missed you," she said lovingly, "dear twin brother."

Now, this time, Harry was confused. A twin sister?! It did not seem to be the truth, as when he traveled his eyes discreetly up and down the girl's body, he noticed that her eyes were a darker shade of brown, her hair was colored with a light tint of red, and small, girly curves hugged and formed her body. She was also pale and a bit skinny, just like him.

He doubted the girl's sudden outburst of them being twins. And if they were twins, Harry thought with a quick spark of anger, why did they get separated? It seemed that the girl was living comfortably, judging by her bag, while he, in his large shirt and baggy pants, was almost being starved all his life.

He stood there, not knowing what to do since the girl was still hugging him.

"Come, I'm going to introduce you to Uncle Ed and Aunt Cath," she said once when she let go of Harry. She threw her empty bottle at a nearby trash can and then pulled the stumbling Harry towards a couple, who were avidly talking to some friends.

"Aunt Cath, Uncle Ed, I've found him! I've found Harry!" she squealed excitedly. The couple turned their heads toward Hailey and Harry. Harry then assumed they were the people Hailey called 'Uncle Ed and Aunt Cath'. He quickly hid behind Hailey, suddenly being shy and nervous, as he knew he was being introduced to his other 'relatives'.

"What? Where? How?" the man asked, confusion evident in his face, which mirrored his wife's.

"Here, at my back. Come on now, Harry. Don't be shy. They won't bite," she assured. Harry, looking at them with somewhat a confused face, slowly went beside Hailey.

"It was nice to meet you, Mr. and Mrs. Potter," he slowly told them.

The couple chuckled good-naturedly. "Call us Uncle Ed and Aunt Cath. It's nice that we've finally found you," said Uncle Ed.

"How did I have a twin sister? How did Dad and Mom have another relatives? Why did you not adopt me too?" Harry was bursting with questions. He wanted badly to know more about his relatives.

Uncle Ed and Aunt Cath exchanged looks and Aunt Cath stroked Harry's hair. "About Hailey," she started to explain, "you were twins, alright, but each of you were different. You look more like James and Hailey looked like Lily."

The train whistle suddenly blew, taking the attention of all in the train station. Hailey and Harry quickly panicked. "Bloody hell, I forgot about the train! Bye uncle, bye auntie," she said, waving.

"Yeah. Bye," Harry seconded, following the girl into the train.

The train started moving and they latched onto the door, Harry running quickly to catch Hailey's hand. Hailey bit her lip in excitement as Harry caught her hand. She pulled him on and once they were deemed safe, they started laughing and looking out the train window.

"Bye! Don't forget to write us letters! And Hailey! Don't forget the pranks we've taught you! Don't forget your goal!" shouted Uncle Ed as the train was going farther from the station..

"What goal?"

Hailey chuckled as Harry asked curiously. "I should've known," she mumbled to herself, and said albeit louder, "Once a Marauder, always a Marauder."

Harry smiled, although he did not completely understand what Hailey had just said. .

"Come on, we still need to find an empty compartment for you," Hailey said after a few moments. "I have mine already." The Boy Who Lived nodded and followed Hailey.

"You know what?" Harry said while Hailey led him to a compartment.

"Hmm?" she responded.

He hesitated and slowly replied. "I think this is going to be the best year of my life."

"I don't think so. I know it will be the best year ever."

Hailey chuckled at his words and opened the compartment. There was already four people in the compartment and they were talking animatedly at each other. Hailey and Harry looked at each other and groaned.

"Seems like this is my stop, unless you want to join me," Hailey said to her twin.

"Nah, go ahead. I'm going to find an empty compartment," Harry replied.

"Very well. See you at Hogwarts, Harry," the female brunette said as she watched her brother go.


	3. Chapter 3: The Hogwarts Express

_**Summary:**_ _AU Philosopher's Stone. Harry Potter has a twin sister that we did not know of, up until she went to Hogwarts. Raised by James' younger brother (OC), she grew up to be a prankster but a responsible and talented child. However, imagine the Potters' (including Harry) surprise when she got sorted in the House of Snakes. A bit crestfallen, Hailey Potter manages to find comfort in the name of one Harmony Pettifogger and together, they have an adventure even more dangerous than the Golden Trio's._

 ** _Disclaimer:_** _I do not own Harry Potter._

* * *

The journey to Hogwarts was quite loud and brash; quite unsettling for a girl like her. The conversations around her, they were too loud, considering that she lived in a relatively quiet house (except for when they have prank wars, that is) since her aunt was a healer at Saint Mungos and her uncle was an auror. And a crash from a certain boy named Draco Malfoy made things even harder. She wished Harry and the others were there sitting with her; it felt lonely not knowing anyone. She felt trapped.

As conversations became heated and even more louder outside, she shut her eyes. Her head was spinning… her ears ringing… she wanted to faint… everything was bursting around here…

"Are you okay?" A cool hand was placed upon her shoulder.

She looked up to see a chestnut-haired boy who looked calm. He smiled softly at her, easing her fears temporarily.

She cleared her throat and nodded. "I'm fine," she said, her voice trailing off. "I'm not yet used to being in loud spaces…"

He smiled again. "Don't worry," he replied. "You'll get used to the noise." He then pulled out a pair of earplugs and offered them. "Earplugs?"

Hailey did a quick contemplation in her mind. "...Thanks," she sheepishly said as she took the earplugs. The boy beside her relaxed, leaning on the chair. Silence quickly followed amidst the conversations of three other people in the compartment.

Later the boy spoke up. "What's your name?"

Hailey removed one of the earplugs and turned her head in distraction. "W-what?" she asked, taking one earplug off from her ear.

He repeated the question. "What's your name?" He then held out his hand. "I'm Dave."

"Hailey. Hailey Potter."

Dave blinked for a moment. "Potter?" he repeated. "You're a relative of Harry Potter?" His hand was still in place and his eyebrows were furrowed.

"I couldn't be anybody else than a Potter," Hailey smiled at him and shook his hand.

By now, all eyes were on Hailey and conversations inside the compartment subsided. "How…" was they all managed to say.

Hailey laughed sheepishly. "My dad had a brother, which that brother had a wife but with no children."

One of them looked at the other. He exchanged glances with another too. "You're Harry's sister?!" one of them spluttered. Dave and the other muttered about how lucky Hailey was. Hailey nodded shyly.

"Cool!" They said again. They cheered and were in awe while Hailey cringed at the loud noise until Dave checked his watch and groaned.

"We're close to Hogwarts! Two minutes left to go!" He said, taking out a black robe. The others then started taking their robes out. Hailey glanced at him.

"How did you know that and what do we have to do with that?"

"Just get your robes on," one girl chided. "It's already time."

They were soon ready to go as the train stopped to a halt. As the train completely stopped, students started pouring out of the compartments. Soon, Dave and Hailey were left.

Hailey removed the earplugs and gave them back to Dave. "Thanks," she said.

Dave nodded and went to the door but paused before going. "Hope to see you in Gryffindor," he said as he left. "I'm a second year there." He then walked out, leaving Hailey alone in the compartment.

Hailey nodded, picking up her shoulder bag and adjusting it on her shoulder. "Alright." Then she also left the compartment and down the train.

She was one of the last students to leave the train.


End file.
